脂多糖对复合培养的肺微血管内皮细胞表达IL-6的影响

以脂多糖（LPS）处理与大鼠肺动脉平滑肌细胞复合培养的肺微血管内皮细胞，测定两种细胞培养上清中白细胞介素6（IL-6）的活性，采用RT-PCR方法检测单独培养和复合培养的肺微血管内此细胞正常组以及LPS2h、6h、12h组IL-6基因的表达水平。结果发现，LPS刺激单独培养和复合培养2h组肺微血管内皮细胞和肺动脉平滑肌细胞上清中IL-6的活性均明显增强，8h组两种细胞上清中IL-6的活性均最强，16h组的活性均减弱，24h组的活性低于2h组；两种细胞单独培养组的活性明显强于复合培养组；LPS刺激单独培养和复合培养2h组肺微血管内皮细胞中IL-6mRNA表达水平升高，8h达最高，16h有所降低，但仍高于正常组；单独培养组的IL-6mRNA表达水平明显高于复合培养组。说明LPS可促进单独培养和复合培养的两种细胞培养上清中IL-6活性升高，增强单独培养和复合培养的肺微血管内皮细胞中IL-6基因的表达，复合培养可使IL-6活性和基因水平降低。

EFFECT OF LIPOPOLYSACCHARIDE ON EXPRESSION OF INTERLEUKIN-6 IN COCULTURED LUNG MICROVASCULAR ENDOTHELIAL CELLS

Rat lung microvascular endothelial cells (LMVEC) were cocultured with rat pulmonary arterial smooth muscle cells (PASMC). The cultures were divided into 5 groups: normal group (N), lipopolysaccharide (LPS) 2h (L 2), LPS 8h (L 8), LPS 16h (L 16 ), and LPS 24h (L 24 ). The activity of IL 6 in LMVEC and PASMC supernatants was determined by radio immunity method, and the expression level of IL 6 mRNA in LMVEC was detected with RT PCR. The results showed that the activity of IL 6 in LMVEC and PASMC was enhanced by LPS at L 2, reaching the higher level after 8 hour stimulation. Furthermore, the activity of IL 6 was stronger in homotypic groups than that of coculture groups. The expression of IL 6 mRNA in LMVEC was increased in L2 group, and highest in L6 group, but lowered in L12 group, though it was still stronger than that of N. It suggest that IL 6 mRNA and the activity of IL 6 in LMVEC and PASMC were enhanced in both homotypic and coculture groups by LPS. And the mRNA level and activity of IL 6 were higher in homotypic groups than that of coculture groups.